z-buffer

(computer graphics) A buffer for the purpose of tracking the relativedepths of different objects in a scene and determining which are closer to the observer than others.

z buffer - Computer Definition

A memory buffer in a graphics accelerator that is used to speed up the rendering of 3D images. It holds the depth of each pixel (z-axis), and as an image is drawn, each pixel is matched against the z buffer location. If the next pixel in line to be drawn is below the one that is already there, it is ignored. This is also known as "hidden surface removal." See graphics pipeline and graphics accelerator.